This invention relates generally to bale wagons, and specifically to a two-position trip arm for sensing the presence of bales in either a first or second location on the bale-receiving area of a bale wagon and activating a transfer means.
Over the past years, the three-table bale wagons, such as that disclosed in U.S. Pat. No. 2,848,127 to G. E. Grey has become by far the most successful commercial apparatus of its kind. From a study of the Grey patent referred to above, one will readily appreciate that the bale wagon shown therein includes three tandemly arranged tables, each pivotally mounted about a transverse axis relative to the longitudinal center line of the wagon. Bales of hay are picked up from the field and conveyed onto a first receiving table which pivots upwardly about its transverse axis to deposit the bales on a rearwardly disposed transfer table. The receiving table continues to receive bales and deposit the bales received on the transfer table until a tier of bales has been accumulated thereon. Once a full tier of bales has been accumulated on the transfer table, the transfer table is pivoted upwardly about its transverse axis, causing the tier of bales to be deposited on a rearwardly disposed load bed. The transfer table continues to function as a bale-accumulator, and continues to deposit the tiers formed thereon in succession on said load bed until a stack of bales is formed thereon, the stack being comprised of a series of side-by-side tiers. Once the stack has been formed on the load, the wagon can then deposit the entire stack on the ground or on some other storage surface by pivoting the load bed about its transverse axis.
Another type of bale wagon demonstrated to successfully and efficiently form stacks of bales is disclosed, for example, in co-pending U.S. Patent Application Ser. No. 891,890, entitled "Bale Wagon" filed concurrently herewith in the name of L. D. Butler and assigned to the same assignee as the instant application. The application mentioned immediately above is hereby expressly incorporated herein in its entirety by reference. This bale wagon, though somewhat similar to the above-described Grey-type bale wagon, has a bale-receiving area which is stationary and at substantially the same height as the tier-forming table. Instead of a pivoting first table the bales are pushed across the bale-receiving area onto the tier-forming table by a horizontal pusher mechanism. The machine tier-forming table and a load rack then function substantially as described in the Grey patent, and generally known in the art.
The overall objective of a bale wagon is to form a uniform stack which is stable and permits the bales to weather in a proper manner. In order to enhance the stability of the stack, it is generally desirable to provide one or more tie tiers within the stack, such being tiers having individual bales arranged to overlap two bales in adjacent tiers above and below the tie tier. In the more conventional Grey-type automatic bale wagon, the formation of one or more tie tiers is accomplished during the formation of the stack on the bale wagon through utilization of a mechanization which is similar to that illustrated and described in U.S. Pat. No. 3,395,814. In the above-identified incorporated application, the tiers are formed partly through the use of swing arms which engage in-line bales and pivot them through approximately 90.degree..
That portion of the tier forming process which is of importance to the instant invention relates to the ability of the wagon control system to sense the position of a single bale at the center portion of the bale-receiving means or, in the alternative, the full-load position of the bale-receiving means. As shown and described in the above noted U.S. Pat. No. 3,395,814 and in U.S. Pat. No. 3,901,393, the formation of standard tier patterns require activation of the transfer means only when the bale-receiving means is completely loaded, and the formation of the tie tiers requires the same ability, plus the ability to sense the locations of a single bale in the center of the bale-receiving means. In known machines, either two sensing means have been employed on the bale-receiving means or the operator has been required to activate the transfer means upon visual observation of bale location.
The invention to be described below permits complete control and sensing of bale position on the bale-receiving means in a manner which increases the overall efficiency of the automatic formation of tied stacks.